A spine comprises vertebrae which are a series of small bones, and also includes spinous processes. A spinous process is one of two bony protrusions arising from the posterior side of each vertebra in the human spine. Extending backwards and downwards from the main body of the vertebra, each spinous process is an extension of the lamina. The laminae are two bony plates that converge at the back of each vertebra to form the vertebral arch. The spinous processes curve outward from this junction. A variety of scenarios may exist where damage to the spine may occur including, but not limited to, injury or illness. Severe, even debilitating, pain can result from such damage. In some instances, artificial assistance may be necessary to address such damage.
Surgical procedures exist that attempt to address such damage including using various vertebral fixation devices. Conventional devices exist to implant vertebrae fixation devices, but such devices often suffer from the problem of being purely manual and are usually complex. Such manual devices require the use of human muscle, which can fatigue, to perform the procedure. Moreover, the incision opening for insertion of these fixation devices may require substantial openings to achieve access to the spinous process.
There are drawbacks associated with the known conventional fixation devices and methodologies. For example, present methods for installing a conventional fixation device often require that the adjacent vertebral bodies be distracted to restore a diseased disc space to its normal or healthy height prior to implantation of the fixation device. In order to maintain this height once the fixation device is inserted, the fixation device is usually dimensioned larger in height than the initial distraction height. This difference in height can make it difficult for a surgeon to install the fixation device in the distracted intervertebral space.
As such, there exists a need for a fixation device capable of being installed inside an intervertebral disc space at a minimum to no distraction height and for a fixation device that can maintain a normal distance between adjacent vertebral bodies when implanted.